The Tissue Bank and Pathology Core will have several functions that directly support the research investigators in this program project. Collection, storage, and cataloging of biopsies and surgical tissue specimens from oral cancers and precancers will be an essential goal; this will include the handling of specimens from animal models. Research investigators on the four major projects and the pilot projects will be provided frozen and paraffin-embedded tissue sections from oral cancerous and precancerous lesions as needed. A substantial numb3er (>3000) of archived and frozen biopsy specimens already have been formally organized as part of existing tissue bank for the UCSF Oral Cancer Research Center. Specimen information has been stored in an Access database. This database will be maintained to manage all data related to patients and clinical samples. Within the Tissue Bank, diagnostic groups include hyperplasia, hyperkeratosis, dysplasia, carcinoma in situs, verrucous carcinoma, and invasive squamous cell carcinoma, and invasive squamous cell carcinomas, and include several cohorts of SCC that are of biologic, etiologic, and/or pathogenetic significance, such as patients who have serial biopsies from a single oral region, patients in age group <35 years, and patients with oral dysplasias that progressed to SCC and others in which the dysplasia did not transform to SCC. New fresh and fixed specimens will be received from oral and surgical pathology with the assistance of personnel in the UCSF Cancer Center. Implementation of a universal surgical consent form will allow us to link fresh surgical specimens with patients through either medical chart review or the UCSF Cancer Registry. The Stomatology Clinical Center will continue to be valuable source of unfixed precancerous lesions. Outcome information on archived surgical specimens will continue to be added to the database through the cooperation of the UCSF Cancer Registry. Technical and consultative services in biostatistics, histopathology and immunohistochemistry will be provided to all investigators.